Comments on: Jerry Coyne on race: a reflection of evolutionhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/
Wed, 04 Dec 2013 06:45:00 +0000hourly1http://wordpress.org/?v=4.0.5By: Sandgroperhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40809
Tue, 06 Mar 2012 12:26:08 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40809It suggests a sophistication of thought and concepts that might not be expected. I guess they could have experimented with very small quantities of new/unknown plants, which is what you would be inclined to do, right? But even so, there had to be the chain of thought “Hmmm, that made me sick, but it’s otherwise pretty tasty – I need to process it somehow to get rid of whatever is in it that is doing that.” And then to figure out the multi-step process. That’s what really boggles me. But then Aboriginal people allegedly had a pharmacopoeia of thousands of plants (only partly documented), so figuring out how to detoxify a potential food source would probably have been relatively simple for them.

Justin, that Spanish guy had to have been as dumb as sh*t. In real life, Papuans are some of the most distinctive people I have seen.

I could get a bunch of Torres Strait Islanders and Aborigines from northern Queensland and mix them up, and I’m willing to bet you would have no difficulty in separating them into two correct groups, just on physical appearance.

]]>By: Barbarahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40808
Tue, 06 Mar 2012 06:16:13 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40808Sandgroper: “how the hell did they find out what they needed to do to the plants to render them non-toxic?”

Yes — I’m amazed that people figured out the complex, multi-step, often lengthy methods needed to detoxify some plants.

40. Sandgroper, all you _insert people_ look the same from the eyes of the other, duh! What if they were both from Guinea! ;p

]]>By: Sandgroperhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40806
Mon, 05 Mar 2012 19:12:23 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40806I don’t believe I would ever mistake a Papuan for an African.
]]>By: LongMahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40805
Mon, 05 Mar 2012 10:31:07 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40805I”m watching a special right now on Dr. Nina Jablonski and her belief that folate deficiency, which she claims is the leading factor in determining how skin color developed in humans.
]]>By: Eddyhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40804
Mon, 05 Mar 2012 07:34:30 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40804@DK

Interesting. So that would mean that the average FST between dog breeds would be around .25 – .3 (Roughly the distance between Papuans and/or Melanesians and Africans)

Strange that Papuans and Africans are the most genetically distant (unless I’m again mistaken) but could pretty much pass for each other in many cases.

]]>By: Sandgroperhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40803
Mon, 05 Mar 2012 05:56:03 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40803Yep, workers shelling cashews need to wear protective gloves, due to the anarcardic acid in the shell. I’ve been to a cashew ‘factory’ in southern Thailand where they were doing exactly that.
]]>By: Justin Giancolahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40802
Sun, 04 Mar 2012 21:38:11 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40802^Okinawans did the same. And cashews, found in Indonesia I believe?, are originally toxic unless treated. Seems you guys in that part of the world are good at that.

The cashews actually burn your skin! – even more on point!

]]>By: Sandgroperhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40801
Sun, 04 Mar 2012 09:09:41 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40801Barbara: “And of course it takes a while for a population to develop an understanding of which plants are toxic, as they enter new ecoregions.”

Australian Aboriginal people ate some plants native only to Australia that were very toxic unless subjected to quite lengthy and complex multi-stage processing to leach out the toxins.

My question is – how the hell did they find out what they needed to do to the plants to render them non-toxic?

I have this sort of comical mental model of the women using disposable male ‘test subjects’ while they experimented, but that’s clearly not the answer.

]]>By: Barbarahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40800
Sat, 03 Mar 2012 21:38:55 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40800Interesting that chamomile would cause photosensitization. I know two people who suffered serious skin burns (scarring in one case) from contact with sap of parsnips (Pastinaca) and cow parsnip (Heracleum). Eating St. John’s wort (Hypericum) and vegetation of buckwheat (Fagopyrum) can cause it.

In addition, many plants can cause liver damage that prevents the liver from breaking down phylloerythrin (produced by breakdown of chlorophyll), thus causing photosensitization.

Relevance to selection for human skin pigmentation might be suggested by this description of symptoms in non-human mammals: Both light and the presence of a reactant substance in the peripheral circulation are required. Therefore, the reaction will occur only in areas of unpigmented or lightly pigmented skin which is not covered by a dense light-screening coat of hair. . . . white sheep are affect particularly about the head, and cattle on white or unpigmented areas of the skin . . . Black-skinned animals are resistant, but may not prove immune to massive exposures. (Kingsbury1964, p. 35)

Although humans would probably tend to avoid eating plants that cause photosensitization, choices would be limited during times of famine. And of course it takes a while for a population to develop an understanding of which plants are toxic, as they enter new ecoregions.

]]>By: Tom Brihttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40798
Fri, 02 Mar 2012 23:38:54 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40798Hi Barbara, Sorry if I implied that aggression was a trait sought by dairy breeders. As you said, it is simply a side effect, undesired.

As for photo-sensitization, chamomile is one culprit. I had a fair-skinned friend who liked chamomile. We were living in the sub-tropics. I suggested he quit drinking it after he complained about getting sensitive to the sun.

Regarding hardwired racism.. Hyenas that have never encountered Lions will become aggressive around items that smell like lions. I know this is an extreme example but I think you have a point.

Regarding “g” as a measure of race. Even the most g-loaded tests can be studied for. Engineers are often ‘trained’ to be better at these kind of ‘creative logistic’, ‘puzzle’ problems. Children exposed to puzzles early when intelligence hasn’t yet crystallized also perform much better on these tests as adults. If you’ve ever seen the questions on an IQ tests you’d know that the high heritability estimates from certain studies to be questionable at best (Examples if requested). Even assuming high (60% + etc.) heritability the Flynn effect shows that populations cognitive levels can go up 2 standard deviations in 2-3 generations.

Also there is increasing evidence for multiple forms of intelligence. For example, hyenas are better ‘group problem solvers’ than even Chimpanzees who outperform them in every other cognitive field by far.

Regarding dog breeds as examples of race.. Correct me if I’m wrong but isn’t the separation among breeds of dog roughly 3-5x greater than the separation of human clusters?

To me, race seems determined by visibly observable traits and by culture more than anything.

]]>By: Ianhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40796
Fri, 02 Mar 2012 22:14:46 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40796When I was younger, I thought of human races as archetypes, and the variation between them a product of mixing. I blame it on the fact that I read Coon when I was about 14. Still, as a (half)Indian, it’s hard to see reconcile the reality of a billion people in the subcontinent with models that try to classify people into 3-5 races. As I learned more biology, I came to the conclusion that human variation was clinal, and race was really an artefact of where you chose to sample along the continuum…as a plant ecologist, I think about things like that a lot. (I’m also somewhat skeptical of ecozones.)

Thanks to a number of convergent strands (of which Razib’s blogging has been a key element), I have come to a rather different conclusion. Race, in my opinion, is more a feature of agriculture than evolution.

Consider two possible models of race: Model 1, in which sharp distinctions existed before the Neolithic, and have been maintained and enhanced as certain groups adopted agriculture and displaced their hunter-gatherer neighbours; and Model 2, in which variation was clinal prior to the Neolithic, but that the immense demographic expansion of certain groups expanded THEIR specific points on the continuum, and brought them into contact (or nearly into contact) with other expansionist agriculturalists.

To me, the Model 2 seems more plausible than Model 1. Is that an argument against race? No, but it does suggest that races shouldn’t really be seen as “locally adapted optima” and rather, should be seen more as transient phenomena produced by historic contingency. Whether this means that race is “real” or not is, to me, a little beside the point. But I’m not convinced by Coyne’s argument that these differences represent the “accumulation of genetic differences between isolated populations”.

]]>By: Martinhttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40795
Fri, 02 Mar 2012 20:26:41 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40795Hey Razib, one of the most interesting aspect of that article was in the comments section, somebody pointed out a seemingly serious mathematical flaw in the entire Fst = human biodiversity issue, and the ‘more variation within groups than between’ argument.

” when within-group variation is high, the between-group variation is ALWAYS small compared to the within-group variation, and the ratio of between-group variation to total variation approaches zero, even if the groups share no genes whatsoever”

ie, the only way to meaningfully do this, would be by comparisons of Absolute differences. (he said that it was a better indicator of true evolutionary divergence for fruitflies than Fst )

Can you comment on this, or perhaps write a blog entry, would love to hear your opinion!

]]>By: Jason Antrosiohttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40794
Fri, 02 Mar 2012 04:17:22 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40794In a recent comment to my blog-post on these issues, Henry Harpending suggested taking a look at the work of Guido Barbujani. As Harpending enjoined: “Why chatter about something when one can come up with a ruler and measure it?”

Barbujani’s measurements are indeed quite instructive–I recommend his 2010 paper (co-authored with Vincenza Colonna) as a careful overview relevant to both the post from Jerry Coyne and some of the comments in this stream. Please see Human genome diversity: frequently asked questions, and I’m grateful to Harpending for a very helpful resource.

Interestingly, both Harpending and Coyne use the metaphor of human genetic diversity as a “lumpy pudding.” I’m not sure if this is an old trope for geneticists or a new trend, but here is Coyne on the issue:

“As I said, this doesn’t show that there are discrete ‘races’ in Europe, and I don’t think there are obviously discrete ‘races’ anywhere these days, though there is large-scale genetic differentiation among worldwide population suggesting that such races once existed as relatively discrete and geographically isolated populations. The discreteness that once existed, or so I think, is now blurring out as transportation and migration are beginning to mix the discrete groups into not a melting pot, but sort of a lumpy pudding of humanity.”

Coyne is not entirely incorrect, but his notion that discreteness once existed but is only “now blurring” with what he termed in the previous post “recent innovations in transportation” is odd–is he talking about airplanes of the last 50 years, the railroads of the last 150 years, or the transoceanic voyages of the last 500?

Coyne’s idea of ancient discreteness only recently turned into lumpy pudding is unsupported—not by Barbujani and Colonna’s 2010 review, not by the 2009 material I’ve been referencing from “Race Reconciled”, not from what I read on Dienekes blog, not from what I get from John Hawks: admixture is ancient and normal, not recent and exceptional.

]]>By: Barbarahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40793
Thu, 01 Mar 2012 23:34:52 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40793Re: selection of dairy bulls. Breeders did not select for “masculine” bulls but for bulls whose mothers, sisters, etc., produced more milk than most dairy cows. The dangerous aggression seen in modern dairy bulls was a by-product of the selection, not the object of it, as implied above.
]]>By: Barbarahttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40792
Thu, 01 Mar 2012 23:32:21 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40792Re: human skin pigmentation and sunlight. Maybe there’s a third player — plants. In a number of plant species, eating the plant or even touching the sap can cause photosensitization. If the pale-skinned individual is exposed to bright sunlight after interacting with the plant, chemicals from the plant block capillaries. This can result in unusually severe sunburn or (in sheep) in loss of ears, lips, etc. The results can be fatal, sometimes from starvation. Hunter/gatherer humans must have been exposed to these plants often, and at young ages. This could produce selection for dark skin, especially where sun is bright.
]]>By: Tom Brihttp://blogs.discovermagazine.com/gnxp/2012/02/jerry-coyne-on-race-a-reflection-of-evolution/#comment-40791
Thu, 01 Mar 2012 16:28:32 +0000http://blogs.discovermagazine.com/gnxp/?p=15916#comment-40791May be relevant, cattle breeders many years ago observed that extremely masculine bulls produce daughters that are more feminine, will have higher milk production. So in the dairy breeds there is selection for more masculine bulls. In beef breeds there is no point in increasing milk production, so they are not selected for hyper-masculinity, but are for fast growth. Beef bulls tend to be less aggressive, less dangerous to work with than dairy bulls.

Be interesting to see if there is any correlation between father masculinity and daughter femininity in humans.

I have to admit I don’t have a very deep understanding of fst or pop gen statistical methods so I am fumbling in the dark a bit here but the research I did on sub species as an undergrad always left me with the impression that continental races fit rather well into general usage of sub species for other animals.